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Monday, May 21, 2012

Lawrence Krauss refers to the 120 orders of magnitude for Dark Energy error in 'A Universe from Nothing' in the Chapter 'Much Ado about Nothing' pg. 72. It is the 'Cosmological Constant Problem' made explicit by Yakov Zel'dovich in 1967.

"I think at some point you need to provoke people. Science is meant to make people uncomfortable."

... (picture)

It is hard to know how our future descendants will regard the little sliver of history that we live in. It is hard to know what events will seem important to them, what the narrative of now will look like to the twenty-fifth century mind. We tend to think of our time as one uniquely shaped by the advance of technology, but more and more I suspect that this will be remembered as an age of cosmology---as the moment when the human mind first internalized the cosmos that gave rise to it. Over the past century, since the discovery that our universe is expanding, science has quietly begun to sketch the structure of the entire cosmos, extending its explanatory powers across a hundred billion galaxies, to the dawn of space and time itself. It is breathtaking to consider how quickly we have come to understand the basics of everything from star formation to galaxy formation to universe formation. And now, equipped with the predictive power of quantum physics, theoretical physicists are beginning to push even further, into new universes and new physics, into controversies once thought to be squarely within the domain of theology or philosophy.

In January, Lawrence Krauss, a theoretical physicist and Director of the Origins Institute at Arizona State University, published A Universe From Nothing: Why There Is Something Rather Than Nothing, a book that, as its title suggests, purports to explain how something---and not just any something, but the entire universe---could have emerged from nothing, the kind of nothing implicated by quantum field theory (crabsallover Wikipedia link). But before attempting to do so, the book first tells the story of modern cosmology, whipping its way through the big bang to microwave background radiation and the discovery of dark energy. It's a story that Krauss is well positioned to tell; in recent years he has emerged as an unusually gifted explainer of astrophysics. One of his lectures has been viewed over a million times on YouTube and his cultural reach extends to some unlikely places---last year Miley Cyrus came under fire when she tweeted a quote from Krauss that some Christians found offensive. Krauss' book quickly became a bestseller, drawing raves from popular atheists like Sam Harris and Richard Dawkins, the latter of which even compared it to The Origin of Species for the way its final chapters were supposed to finally upend the "last trump card of the theologian."

By early spring, media coverage of "A Universe From Nothing" seemed to have run its course, but then on March 23rd the New York Times ran a blistering review of the book, written by David Albert, a philosopher of physics from Columbia University. Albert, who has a PhD in theoretical physics, argued that Krauss' "nothing" was in fact a something and did so in uncompromising terms:

"The particular, eternally persisting, elementary physical stuff of the world, according to the standard presentations of relativistic quantum field theories, consists (unsurprisingly) of relativistic quantum fields... they have nothing whatsoever to say on the subject of where those fields came from, or of why the world should have consisted of the particular kinds of fields it does, or of why it should have consisted of fields at all, or of why there should have been a world in the first place. Period. Case closed. End of story."

Because the story of modern cosmology has such deep implications for the way that we humans see ourselves and the universe, it must be told correctly and without exaggeration---in the classroom, in the press and in works of popular science. To see two academics, both versed in theoretical physics, disagreeing so intensely on such a fundamental point is troubling. Not because scientists shouldn't disagree with each other, but because here they're disagreeing about a claim being disseminated to the public as a legitimate scientific discovery. Readers of popular science often assume that what they're reading is backed by a strong consensus. Having recently interviewed Krauss for a different project, I reached out to him to see if he was interested in discussing Albert's criticisms with me. He said that he was, and mentioned that he would be traveling to New York on April 20th to speak at a memorial service for Christopher Hitchens. As it happened, I was also due to be in New York that weekend and so, last Friday, we were able to sit down for the extensive, and at times contentious, conversation that follows.

I know that you're just coming from Christopher Hitchens' memorial service. How did that go?

Krauss: It was a remarkable event for a remarkable man, and I felt very fortunate to be there. I was invited to give the opening presentation in front of all of these literary figures and dignitaries of various sorts, and so I began the only way I think you can begin, and that's with music from Monty Python. That got me over my initial stage fright and my concern about what to say about someone as extraordinary as Christopher. I was able to talk about a lot of the aspects of Christopher that people may not know about, including the fact that he was fascinated by science. And I also got to talk about what it felt like to be his friend.

I closed with an anecdote, a true story about the last time I was with him. I was reading the New York Times at his kitchen table, and there was an article about the ongoing effort to keep Catholic students at elite colleges like Yale from losing their faith. The article said something like "faced with Nietzsche, coed dorms, Hitchens, and beer pong, students are likely to stray." There are two really amazing aspects of that. For one, to be so culturally ubiquitous that you can be mentioned in a sentence like that without any further explanation is pretty exceptional. But also to be sandwiched between "Nietzsche" and "beer pong" is an honor that very few of us can ever aspire to.

I want to start with a general question about the relationship between philosophy and physics. There has been a fair amount of sniping between these two disciplines over the past few years. Why the sudden, public antagonism between philosophy and physics?

Krauss: That's a good question. I expect it's because physics has encroached on philosophy. Philosophy used to be a field that had content, but then "natural philosophy" became physics, and physics has only continued to make inroads. Every time there's a leap in physics, it encroaches on these areas that philosophers have carefully sequestered away to themselves, and so then you have this natural resentment on the part of philosophers. This sense that somehow physicists, because they can't spell the word "philosophy," aren't justified in talking about these things, or haven't thought deeply about them---

Is that really a claim that you see often?

Krauss: It is. Philosophy is a field that, unfortunately, reminds me of that old Woody Allen joke, "those that can't do, teach, and those that can't teach, teach gym."

And the worst part of philosophy is the philosophy of science; the only people, as far as I can tell, that read work by philosophers of science are other philosophers of science. It has no impact on physics what so ever, and I doubt that other philosophers read it because it's fairly technical. And so it's really hard to understand what justifies it. And so I'd say that this tension occurs because people in philosophy feel threatened, and they have every right to feel threatened, because science progresses and philosophy doesn't.

.... (picture) Lawrence Krauss, author of "A Universe From Nothing: Why There Is Something Rather Than Nothing"

On that note, you were recently quoted as saying that philosophy "hasn't progressed in two thousand years." But computer science, particularly research into artificial intelligence was to a large degree built on foundational work done by philosophers in logic and other formal languages. And certainly philosophers like John Rawls have been immensely influential in fields like political science and public policy. Do you view those as legitimate achievements?

Krauss: Well, yeah, I mean, look I was being provocative, as I tend to do every now and then in order to get people's attention. There are areas of philosophy that are important, but I think of them as being subsumed by other fields. In the case of descriptive philosophy you have literature or logic, which in my view is really mathematics. Formal logic is mathematics, and there are philosophers like Wittgenstein that are very mathematical, but what they're really doing is mathematics---it's not talking about things that have affected computer science, it's mathematical logic. And again, I think of the interesting work in philosophy as being subsumed by other disciplines like history, literature, and to some extent political science insofar as ethics can be said to fall under that heading. To me what philosophy does best is reflect on knowledge that's generated in other areas.

I'm not sure that's right. I think that in some cases philosophy actually generates new fields. Computer science is a perfect example. Certainly philosophical work in logic can be said to have been subsumed by computer science, but subsumed might be the wrong word---

Krauss: Well, you name me the philosophers that did key work for computer science; I think of John Von Neumann and other mathematicians, and---

But Bertrand Russell paved the way for Von Neumann.

Krauss: But Bertrand Russell was a mathematician. I mean, he was a philosopher too and he was interested in the philosophical foundations of mathematics, but by the way, when he wrote about the philosophical foundations of mathematics, what did he do? He got it wrong.

But Einstein got it wrong, too---

Krauss: Sure, but the difference is that scientists are really happy when they get it wrong, because it means that there's more to learn. And look, one can play semantic games, but I think that if you look at the people whose work really pushed the computer revolution from Turing to Von Neumann and, you're right, Bertrand Russell in some general way, I think you'll find it's the mathematicians who had the big impact. And logic can certainly be claimed to be a part of philosophy, but to me the content of logic is mathematical.

Do you find this same tension between theoretical and empirical physics?

Krauss: Sometimes, but it shouldn't be there. Physics is an empirical science. As a theoretical physicist I can tell you that I recognize that it's the experiment that drives the field, and it's very rare to have it go the other way; Einstein is of course the obvious exception, but even he was guided by observation. It's usually the universe that's surprising us, not the other way around.

"It's usually the universe that's surpising us, not the other way around."

Moving on to your book "A Universe From Nothing," what did you hope to accomplish when you set out to write it?

Krauss: Every time I write a book, I try and think of a hook. People are interested in science, but they don't always know they're interested in science, and so I try to find a way to get them interested. Teaching and writing, to me, is really just seduction; you go to where people are and you find something that they're interested in and you try and use that to convince them that they should be interested in what you have to say.

The religious question "why is there something rather than nothing," has been around since people have been around, and now we're actually reaching a point where science is beginning to address that question. And so I figured I could use that question as a way to celebrate the revolutionary changes that we've achieved in refining our picture of the universe. I didn't write the book to attack religion, per se. The purpose of the book is to point out all of these amazing things that we now know about the universe.

Reading some of the reactions to the book, it seems like you automatically become strident the minute you try to explain something naturally.

Richard Dawkins wrote the afterword for the book---and I thought it was pretentious at the time, but I just decided to go with it---where he compares the book to The Origin of Species. And of course as a scientific work it doesn't some close to The Origin of Species, which is one of the greatest scientific works ever produced. And I say that as a physicist; I've often argued that Darwin was a greater scientist than Einstein. But there is one similarity between my book and Darwin's---before Darwin life was a miracle; every aspect of life was a miracle, every species was designed, etc. And then what Darwin showed was that simple laws could, in principle, plausibly explain the incredible diversity of life. And while we don't yet know the ultimate origin of life, for most people it's plausible that at some point chemistry became biology.

What's amazing to me is that we're now at a point where we can plausibly argue that a universe full of stuff came from a very simple beginning, the simplest of all beginnings: nothing. That's been driven by profound revolutions in our understanding of the universe, and that seemed to me to be something worth celebrating, and so what I wanted to do was use this question to get people to face this remarkable universe that we live in.

... (picture of Socrates and Aristotle)

"Philosophy hasn't progressed in two thousand years."

Your book argues that physics has definitively demonstrated how something can come from nothing. Do you mean that physics has explained how particles can emerge from so-called empty space, or are you making a deeper claim?

Krauss: I'm making a deeper claim, but at the same time I think you're overstating what I argued. I don't think I argued that physics has definitively shown how something could come from nothing; physics has shown how plausible physical mechanisms might cause this to happen. I try to be intellectually honest in everything that I write, especially about what we know and what we don't know.

If you're writing for the public, the one thing you can't do is overstate your claim, because people are going to believe you. They see I'm a physicist and so if I say that protons are little pink elephants, people might believe me. And so I try to be very careful and responsible. We don't know how something can come from nothing, but we do know some plausible ways that it might.

But I am certainly claiming a lot more than just that.

That it's possible to create particles from no particles is remarkable---that you can do that with impunity, without violating the conservation of energy and all that, is a remarkable thing. The fact that "nothing," namely empty space, is unstable is amazing. But I'll be the first to say that empty space as I'm describing it isn't necessarily nothing, although I will add that it was plenty good enough for Augustine and the people who wrote the Bible. For them an eternal empty void was the definition of nothing, and certainly I show that that kind of nothing ain't nothing anymore.

But debating physics with Augustine might not be an interesting thing to do in 2012.

Krauss: It might be more interesting than debating some of the moronic philosophers that have written about my book. Given what we know about quantum gravity (crabsallover Wikipedia link), or what we presume about quantum gravity, we know you can create space from where there was no space. And so you've got a situation where there were no particles in space, but also there was no space. That's a lot closer to "nothing."

But of course then people say that's not "nothing," because you can create something from it. They ask, justifiably, where the laws come from. And the last part of the book argues that we've been driven to this notion---a notion that I don't like---that the laws of physics themselves could be an environmental accident. On that theory, physics itself becomes an environmental science, and the laws of physics come into being when the universe comes into being. And to me that's the last nail in the coffin for "nothingness."

It sounds like you're arguing that 'nothing' is really a quantum vacuum, and that a quantum vacuum is unstable in such a way as to make the production of matter and space inevitable. But a quantum vacuum has properties. For one, it is subject to the equations of quantum field theory. Why should we think of it as nothing?

Krauss: That would be a legitimate argument if that were all I was arguing. By the way it's a nebulous term to say that something is a quantum vacuum in this way. That's another term that these theologians and philosophers have started using because they don't know what the hell it is, but it makes them sound like they know what they're talking about. When I talk about empty space, I am talking about a quantum vacuum, but when I'm talking about no space whatsoever, I don't see how you can call it a quantum vacuum. It's true that I'm applying the laws of quantum mechanics to it, but I'm applying it to nothing, to literally nothing. No space, no time, nothing. There may have been meta-laws that created it, but how you can call that universe that didn't exist "something" is beyond me. When you go to the level of creating space, you have to argue that if there was no space and no time, there wasn't any pre-existing quantum vacuum. That's a later stage.

Even if you accept this argument that nothing is not nothing, you have to acknowledge that nothing is being used in a philosophical sense. But I don't really give a damn about what "nothing" means to philosophers; I care about the "nothing" of reality. And if the "nothing" of reality is full of stuff, then I'll go with that.

"But I don't really give a damn what "nothing" means to philosophers; I care about the "nothing" of reality."

But I don't have to accept that argument, because space didn't exist in the state I'm talking about, and of course then you'll say that the laws of quantum mechanics existed, and that those are something. But I don't know what laws existed then. In fact, most of the laws of nature didn't exist before the universe was created; they were created along with the universe, at least in the multiverse picture. The forces of nature, the definition of particles---all these things come into existence with the universe, and in a different universe, different forces and different particles might exist.

We don't yet have the mathematics to describe a multiverse, and so I don't know what laws are fixed. I also don't have a quantum theory of gravity, so I can't tell you for certain how space comes into existence, but to make the argument that a quantum vacuum that has particles is the same as one that doesn't have particles is to not understand field theory.

I'm not sure that anyone is arguing that they're the same thing--

Krauss: Well, I read a moronic philosopher who did a review of my book in the New York Times (crabsallover link: David Albert in NYT) who somehow said that having particles and no particles is the same thing, and it's not. The quantum state of the universe can change and it's dynamical. He didn't understand that when you apply quantum field theory to a dynamic universe, things change and you can go from one kind of vacuum to another. When you go from no particles to particles, it means something.

I think the problem for me, coming at this as a layperson, is that when you're talking about the explanatory power of science, for every stage where you have a "something,"---even if it's just a wisp of something, or even just a set of laws---there has to be a further question about the origins of that "something." And so when I read the title of your book, I read it as "questions about origins are over."

Krauss: Well, if that hook gets you into the book that's great. But in all seriousness, I never make that claim. In fact, in the preface I tried to be really clear that

you can keep asking "Why?" forever. At some level there might be ultimate questions that we can't answer, but if we can answer the "How?" questions, we should, because those are the questions that matter. And it may just be an infinite set of questions, but what I point out at the end of the book is that the multiverse may resolve all of those questions.

From Aristotle's prime mover to the Catholic Church's first cause, we're always driven to the idea of something eternal. If the multiverse really exists, then you could have an infinite object---infinite in time and space as opposed to our universe, which is finite. That may beg the question as to where the multiverse came from, but if it's infinite, it's infinite. You might not be able to answer that final question, and I try to be honest about that in the book. But if you can show how a set of physical mechanisms can bring about our universe, that itself is an amazing thing and it's worth celebrating. I don't ever claim to resolve that infinite regress of why-why-why-why-why; as far as I'm concerned it's turtles all the way down. The multiverse could explain it by being eternal, in the same way that God explains it by being eternal, but there's a huge difference: the multiverse is well motivated and God is just an invention of lazy minds.

In the past you've spoken quite eloquently about the Multiverse, this idea that our universe might be one of many universes, perhaps an infinite number. In your view does theoretical physics give a convincing account of how such a structure could come to exist?

Krauss: In certain ways, yes---in other ways, no.

There are a variety of multiverses that people in physics talk about. The most convincing one derives from something called inflation, which we're pretty certain happened because it produces effects that agree with almost everything we can observe. From what we know about particle physics, it seems quite likely that the universe underwent a period of exponential expansion early on. But inflation, insofar as we understand it, never ends---it only ends in certain regions and then those regions become a universe like ours. You can show that in an inflationary universe, you produce a multiverse, you produce an infinite number of causally separated universes over time, and the laws of physics are different in each one.

There's a real mechanism where you can calculate it. And all of that comes, theoretically, from a very small region of space that becomes infinitely large over time.

There's a calculable multiverse; it's almost required for inflation---it's very hard to get around it. All the evidence suggests that our universe resulted from a period of inflation, and it's strongly suggestive that well beyond our horizon there are other universes that are being created out of inflation, and that most of the multiverse is still expanding exponentially.

... (picture)

An artist's rendering of the multiverse.

Is there an empirical frontier for this? How do we observe a multiverse?Krauss: Right. How do you tell that there's a multiverse if the rest of the universes are outside your causal horizon? It sounds like philosophy. At best. But imagine that we had a fundamental particle theory that explained why there are three generations of fundamental particles, and why the proton is two thousand times heavier than the electron, and why there are four forces of nature, etc. And it also predicted a period of inflation in the early universe, and it predicts everything that we see and you can follow it through the entire evolution of the early universe to see how we got here. Such a theory might, in addition to predicting everything we see, also predict a host of universes that we don't see. If we had such a theory, the accurate predictions it makes about what we can see would also make its predictions about what we can't see extremely likely. And so I could see empirical evidence internal to this universe validating the existence of a multiverse, even if we could never see it directly.

You have said that your book is meant to describe "the remarkable revolutions that have taken place in our understanding of the universe over the past 50 years--revolutions that should be celebrated as the pinnacle of our intellectual experience." I think that's a worthy project and, like you, I find it lamentable that some of physics' most extraordinary discoveries have yet to fully penetrate our culture. But might it be possible to communicate the beauty of those discoveries without tacking on an assault on previous belief systems, especially when those belief systems aren't necessarily scientific?

Krauss: Well, yes. I'm sympathetic to your point in one sense, and I've had this debate with Richard Dawkins; I've often said to him that if you want people to listen to you, the best way is not to go up to them and say, "You're stupid." Somehow it doesn't get through.

It's a fine line and it's hard to tell where to fall on this one.

What drove me to write this book was this discovery that the nature of "nothing" had changed, that we've discovered that "nothing" is almost everything and that it has properties. That to me is an amazing discovery. So how do I frame that? I frame it in terms of this question about something coming from nothing. And part of that is a reaction to these really pompous theologians who say, "out of nothing, nothing comes," because those are just empty words. I think at some point you need to provoke people. Science is meant to make people uncomfortable. And whether I went too far on one side or another of that line is an interesting question, but I suspect that if I can get people to be upset about that issue, then on some level I've raised awareness of it.

The unfortunate aspect of it is, and I've come to realize this recently, is that some people feel they don't even need to read the book, because they think I've missed the point of the fundamental theological question. But I suspect that those people weren't open to it anyway.

I think Steven Weinberg said it best when he said that science doesn't make it impossible to believe in God, it just makes it possible to not believe in God. That's a profoundly important point, and to the extent that cosmology is bringing us to a place where we can address those very questions, it's undoubtedly going to make people uncomfortable.

It was a judgment call on my part and I can't go back on it, so it's hard to know.

You've developed this wonderful ability to translate difficult scientific concepts into language that can enlighten, and even inspire a layperson. There are people in faith communities who are genuinely curious about physics and cosmology, and your book might be just the thing to quench and multiply that curiosity. But I worry that by framing these discoveries in language that is in some sense borrowed from the culture war, that you run the risk of shrinking the potential audience for them---and that could ultimately be a disservice to the ideas.

Krauss: Ultimately, it might be. I've gone to these fundamentalist colleges and I've gone to Fox News and it's interesting, the biggest impact I've ever had is when I said, "you don't have to be an atheist to believe in evolution." I've had young kids come up to me and say that affected them deeply. So yes it's nice to point that out, but I actually think that if you read my book I never say that we know all the answers, I say that it's pompous to say that we can't know the answers. And so yeah I think that maybe there will be some people who are craving this stuff and who won't pick up my book because of the way I've framed it, but at the same time I do think that people need to be aware that they can be brave enough to ask the question "Is it possible to understand the universe without God?" And so you're right that I'm going to lose some people, but I'm hoping that at the same time I'll gain some people who are going to be brave enough to come out of the closet and ask that question. And that's what amazes me, that nowadays when you simply ask the question you're told that you're offending people.

But let me bring that back full circle. You opened this conversation talking about seduction. You're not giving an account of seduction right now.

Krauss: That's true, but let me take it back full circle to Hitchens. What Christopher had was charm, humor, wit and culture as weapons against nonsense, and in my own small way what I try and do in my books is exactly that. I try and infuse them with humor and culture and that's the seduction part. And in this case the seduction might be causing people to ask, "How can he say that? How can he have the temerity to suggest that it's possible to get something from nothing? Let me see what's wrong with these arguments." If I'd just titled the book "A Marvelous Universe," not as many people would have been attracted to it. But it's hard to know. I'm acutely aware of this seduction problem, and my hope is that what I can do is get people to listen long enough to where I can show some of what's going on, and at the same time make them laugh.

Thursday, May 10, 2012

John Templeton Foundation (who have a 'supernaturalistic' rather than a 'naturalistic' worldview) is sponsoring a group of philosophers and physicists in an area of study 'philosophy of cosmology'. I was surprised to see Brian Greene amongst the list of physicists receiving funds from Templeton.

Oxford and Cambridge in partnership with US cluster to establish ‘Philosophy of Cosmology’ as a new field of study. Templeton grant funds initiative at top universities in philosophy

In a new partnership between Oxford and Cambridge, researchers in physics and philosophy Simon Saunders, Joe Silk, and David Wallace at Oxford University, and John Barrow and Jeremy Butterfield at Cambridge, are to join researchers at a cluster of US universities including Columbia University, Yale University, and New York University, to establish the field of philosophy of cosmology as a new branch of philosophy of physics.

The initiative, funded by the John Templeton Foundation, is of three years in duration and will culminate in a major international conference. The enduring impact of the project will be to isolate and clarify the outstanding conceptual problems in the foundations of cosmology, to seed and stimulate future research in the subject, and to define philosophy of cosmology as a new field in its own right, with its own distinctive problems and motivations.

Chief among them, according to Simon Saunders of Oxford University, ‘is the problem of how to compensate for selection effects – of making sense of the so-called ‘anthropic principle’. Even if we knew the structure of the universe, the whole story from beginning to end, what should we expect to see from our particular corner of it? What are the probabilities? And of course that’s what’s relevant to experiments.’ The problem isn’t restricted to the distribution of stars or galaxies; it could extend to the values of supposedly fundamental constants, such as the cosmological constant --- or dark energy, as it is known.

"Explaining the value of the cosmological constant is one of the most critical problems in theoretical physics" says John Barrow, whose book The Anthropic Cosmological Principle, co-written with Frank Tipler, set the agenda for anthropic reasoning in cosmology the last two decades. “This problem goes deeper than merely describing the accelerated expansion of the universe: it requires an understanding of the vacuum, how the quantum nature of reality impacts on the universe as a whole, and what probability means when used to evaluate observed properties of the universe.”

The initiative is being made now in part because cosmology has in recent years turned into a spectacularly successful empirical discipline. But there is another reason too. “One of the key obstacles to progress in understanding the universe as a whole – particularly the early universe -- is the lack of a realist understanding of quantum theory”, says Saunders. “There are different aspects to the realism problem. One of them is about the nature of reality at the microscopic level; another is about how to apply quantum theory to systems ‘from the inside’ – to so-called closed systems. The latter is called the measurement problem. The universe as a whole is closed in this sense.” How then is it possible to apply quantum theory to cosmology – to obtain a genuinely quantum cosmology? “There has been real progress on that front in the last twenty years” Saunders continues. “That’s where our group and the East Coast group has an edge. We are interested in exploring these questions in quantum theories that are free of the measurement problem. Physicists try to be neutral on these questions, but it’s hard to do that and make sense of quantum cosmology”.

A major component of the Oxford-Cambridge project, like that of the US cluster led by Barry Loewer at Rutgers University, is to establish a community of scholars able to engage with such foundational questions in cosmology. To that end Joe Silk at Oxford, and John Barrow at Cambridge, will host a series of lecture courses, to be given by eminent figures in cosmology. These will be filmed and archived on a website dedicated to providing research materials and teaching resources in cosmology. Another component is related to the ‘PLUS’ e-magazine, associated with the Millennium Mathematics Project at Cambridge University, which will house a series of interviews with leaders in cosmology on key questions in foundations. The three-year project will culminate in a major international conference, and the publication of a volume of papers devoted to the philosophy of cosmology.

The US cluster includes Columbia University, Yale University, New York University, and the University of California at Santa Cruz. It encompasses nine scholars: Barry Loewer, Dean Zimmerman, Sheldon Goldstein and Roderich Tumulka of Rutgers; David Albert and Brian Greene of Columbia, Tim Maudlin of New York University, Priya Natarajan of Yale, and Joel Primack of the University of California, Santa Cruz. Loewer, Zimmerman, Albert and Maudlin are philosophers; Goldstein and Tumulka, mathematicians; Greene, Natarajan, and Primack, physicists. The US cluster, like the Oxford-Cambridge partnership, is funded by a $960,000 grant from the John Templeton Foundation."

Monday, May 07, 2012

Lawrence Krauss explains that the universe (which could have arisen from 'nothing'), like evolution, has no purpose.

"Science has taught us to think the unthinkable. Because when nature is the guide -- rather than a priori prejudices, hopes, fears or desires -- we are forced out of our comfort zone. "

"Most of the energy in the observable universe can be found not within galaxies but outside them, in otherwise empty space, which, for reasons we still cannot fathom, "weighs" something. But the use of the word "weight" is perhaps misleading because the energy of empty space is gravitationally repulsive. It pushes distant galaxies away from us at an ever-faster rate. Eventually they will recede faster than light and will be unobservable."

.... "combining the ideas of general relativity and quantum mechanics, it is possible that the entire universe, matter, radiation and even space itself could arise spontaneously out of nothing, without explicit divine intervention. Quantum mechanics' Heisenberg uncertainty principle expands what can possibly occur undetected in otherwise empty space. If gravity too is governed by quantum mechanics, then even whole new universes can spontaneously appear and disappear, which means our own universe may not be unique but instead part of a multiverse."

... ""Why is there something rather than nothing?" Even the laws of physics may be a cosmic accident, with different laws in different universes. Asking why we live in a universe of something rather than nothing may be no more meaningful than asking why some flowers are red and others blue."

.... " if we ask what properties a universe created from nothing would have, it appears that these properties resemble precisely the universe we live in."

... "Does all of this prove that our universe and the laws that govern it arose spontaneously without divine guidance or purpose? No, but it means it is possible!"

... "And that possibility need not imply that our own lives are devoid of meaning. Instead of divine purpose, the meaning in our lives can arise from what we make of ourselves, from our relationships and our institutions, from the achievements of the human mind.

... "Imagining living in a universe without purpose may prepare us to better face reality head on. I cannot see that this is such a bad thing. Living in a strange and remarkable universe that is the way it is, independent of our desires and hopes, is far more satisfying for me than living in a fairy-tale universe invented to justify our existence."

cosmologists are using metaphysical judgements without a sound philosophical foundation (they are using science, not philosophy or metaphysics)

the Big Bang points to supernatural cause of beginning of universe (why?)

Thomas Aquinas 'doctrine of creation' says that all that is, in whatever way or ways it is, depends upon God as cause. (but that's just saying that God did it!)

In summary William E Carroll maintains that:-
'Claims by authors like Hawking in 'The Grand Design' and Krauss in 'A Universe from Nothing' about the explanatory reach of science are ostensibly made on the basis of developments in science, but they are really metaphysical judgments, frequently advanced without a sound philosophical foundation. If there is a metaphysical assumption lurking behind this view, it is that the mere existence of things needs no explanation.'

For Thomas Aquinas (1224-1274) creation is a topic for metaphysics and theology. The doctrine of creation affirms that all that is, in whatever way or ways it is, depends upon God as cause. The natural sciences have as their subject the world of changing things: from subatomic particles to acorns to galaxies. Whenever there is a change there must be something that changes. Whether these changes are biological or cosmological, without beginning or end, or temporally finite, they remain processes. Creation, on the other hand, is the radical causing of the whole existence of whatever exists. Creation is not a change. To cause completely something to exist is not to produce a change in something, is not to work on or with some existing material. When God's creative act is said to be "out of nothing," what is meant is that God does not use anything in creating all that is: it does not mean that there is a change from "nothing" to "something."

"Cosmology and all the other natural sciences offer accounts of change; they do not address the metaphysical and theological questions of creation; they do not speak to why there is something rather than nothing. It is a mistake to use arguments in the natural sciences to deny creation. Similarly, it is a mistake to use arguments in cosmology to seek to confirm the doctrine of creation."

Saturday, May 05, 2012

The Universe from Nothing - see 21' for energy in the space between quarks!

Chris Street http://www.youtube.com/watch?v=7ImvlS8PLIo - 2009 AAI talk that launched Krauss to write 'Universe from Nothing'.- 10m: good explanation (by superimposing galaxies at different times) of why galaxies appear to expanding at a speed proportional to the distance away.-16m: we are all stardust, H,He,Li were created in big bang; rest of elements were formed in star exploding; 100,000 galaxies within a dime - 3 stars (not 10) explode every night.- 18m age of universe 13.72bn-19.45m - energy of Nothing; if nothing weighs something it contributes a term like this. But 'nothing weighs something' sound ridiculous!-20m - laws of quantum mechanics & special relativity at extremely small scales, nothing is really a boiling bubbling brew of virtual particles that are popping in and out of existence in a time scale that you can't see them.- 20m30s - we can't measure virtual particles directly but we can measure their effects indirectly. Empty space is not empty! Empty space is responsible for 90% of your mass.- 22m energy of nothing Vacuum energy is 10x120 times the energy of all matter in the universe (the worst prediction in all of physics) - if that was the case we wouldn't be here! Something about zero (dont understand)25m - Options for Universe are open,closed or flat. Weighing the Universe tells us which of these options are true.28m - x50 is mass of stuff that doesn't shine (dark matter) v normal matter; 90% of universe mass is dark matter. Universe is flat (not open or closed)32m - in a flat universe the total energy of the universe is precisely zero - gravity can have negative energy which balances out the positive energy of matter. A universe with total energy zero means that only such as universe can come from Nothing. No deity required. Quantum fluctuations can produce a universe from nothing.40m - why something rather than nothing? The answer is, there had to be. If you have nothing in quantum mechanics you always get something.41m - before 1998 we assumed that the universe expansion was slowing down; actually found to accelerating. We live in a universe dominated by nothing. 70% of the energy of the universe resides in empty space.43m - we (galaxies) constitute 1% of a universe that is 70% dark energy and 30% dark matter45m - the cosmological constant aka energy of empty space is just right for us now; galaxies can form; if the constant had been bigger eg x50 the energy density of matter, then galaxies would never have formed -46m - anthropic mania: if many universes and the energy of empty space can vary in each one, then only in those that the energy is not much greater than that, will galaxies and us, form.47m Cosmic natural selection; the laws of physics are just an accident (not fixed and change one paramter); if they were any different we would not be here. No fundamental laws. You may find it repugant but it may true.49m- string theory - tiny vibrating strings51m - in a 100 billion years galaxies will be moving away from us at faster than speed of light (its allowed!) and we will not see other galaxies so we will think we are alone in our Milky Way galaxy!